Certain natural environments continue to be fruitful sources of chemical compounds having unusual and unexpected properties, including possible medicinal properties.
In most areas of the world characterized by large species diversity, many plants and animals engage in fierce competition for living space and resource allotment. Certain organisms tend to exhibit unusually high competitive success in such environments. The reasons for such success are several and diverse. Highly successful plants, for example, may produce one or more distinctive chemical compounds that are toxic to nibblers and browsers or that ward off encroaching competitors for living space. Alternatively, there may be other reasons for adaptive success such as a growth rate that is higher than that of competitors, more prolific or efficient reproduction, better drought tolerance, or other characteristic that provides a competitive advantage. In any event, organisms exhibiting competitive success can offer interesting prospects for finding novel chemical compounds having potentially valuable utility in human industry and in medicine.
Blue-green algae (cyanobacteria) have received considerable attention as a source of novel biologically active chemicals. Carter et al., J. Org. Chem. 49:236-244 (1984); Moore et al., J. Am. Chem. Soc. 106:6456-6457 (1984); Barchi et al., J. Am. Chem. Soc. 106:8193-8197 (1984); and Cragg et al., Am. Soc. Pharmacog. Proceedings, abst. no. 185 (1985). In the first of the foregoing cited references, Carter et al. reported an abundance of unique secondary metabolites from the principal mat-forming marine cyanobacterium Lyngbya majuscula (also named Microcoleus lyngbyaceus).